Almost everyone else in Washington DC - some in dread, many in hope - are anticipating something of a spectacle. "I read he'd been considering doing a parade past Trump Tower in New York and then taking a helicopter here and having the official swearing in and another parade as the whole country followed on television," Kris Harris (45), a carer who travelled from North Carolina on Thursday to watch the event, said.

"That would have been so much fun," she added.

"It's not going to happen but it's still Trump, and he knows the world is watching. He'll do something [different] to start off a fantastic presidency. I know we won't be disappointed."

While there is a reassuring familiarity to the ceremonial events, from the handover by the Obamas and the swearing in at Capitol Hill, to the various glitzy inaugural balls, it's Mr Trump's unpredictability that his supporters hope to see today.

This instability also has the potential to exacerbate entrenched divisions.

"Everyone knows Trump prefers not to use scripts and is liable to say anything when a microphone is put in front of him," Tim Sanchez (27), a politics student from New York who travelled to protest, said. "His inauguration speech should be about setting the tone for his presidency, and it should certainly touch on themes of reconciliation and national unity.

"But will he be able to do that? His press conference last week was a car crash, Nazi Germany, Russia and everything, he couldn't help himself...it's really important he doesn't screw up on this speech."

The president-elect, surely, is aware of the importance of these words.

On Wednesday night, in the basement bar at the Baron Tavern in the Northwest of the city, a young woman found herself at the receiving end of a nasty, spittle-laced diatribe from a middle-aged couple who had been sitting next to her.

Her mistake? Revealing her profession. "I had been making small talk and they said they were in town for the inauguration," the 28-year-old, who didn't want to be named, said later.

"I mentioned that my husband works with me in a government role. That set them off, taunting me that we'd be out of a job, that Trump would 'drain the swamp', that somehow I was the establishment.

"It was out of nowhere. They weren't drinking. It was upsetting."

'Drain the Swamp' was a Trump campaign slogan, focusing on what he sees as the "entire corrupt Washington Establishment".

In the region of 800,000 people are expected to attend the inauguration today - down on the estimated 1.8 million who watched Mr Obama's 2009 inauguration - but still a major influx to the city.

And hundreds of thousands more are expected to travel to Washington for various protests, with a Women's March on Saturday among the biggest events. Flashpoints are inevitable.

There is already a low-level tension around the city, which risks spilling into something else: antagonistic triumphalism, perhaps, versus self-righteous condescension? One side looking down its nose and dismissive, the other side snide and taunting?

Most likely it will be just fine, but there's no doubt it could get ugly.

Partly with that in mind, about 28,000 personnel from various agencies including the Secret Service, the FBI and various police departments are working to help ensure the transfer of power goes smoothly.

And plenty of locals are getting the hell out of dodge.

"You're talking about a city where just 4pc went for Mr Trump when they voted," Carl deMenzies (67), from Arlington, said. "This is not history they want to see."

But as Mr Trump would doubtless respond: "Sad!!"

His biggest disappointment is unlikely to be the lack of Democrats in the crowd, but rather the lack of A-list entertainers at the various events after the likes of Elton John, Celine Dion and Kiss turned down invites. But he'll get over it - the big names may have shunned him, but the big money certainly hasn't.

Mr Trump's inaugural committee has pulled in a $100m from a mix of companies, rich donors, and smaller supporters urged into buying, say, number plates and so on. The funds dwarf the record of $53m set by Mr Obama's team in 2009.

But, as with so much surrounding Mr Trump, how much of that money will be spent on the 'low-key' inauguration - and how - is uncertain.

One thing is clear: at 5pm Irish time, Donald J Trump will ascend to the most powerful job in the world.

"I think there is a lot of fear-mongering out there, and a lot of elitism, even though this is democracy at work," Susan Anthony (52) a retired nurse from El Paso, Texas, argued. "Our new president is going to do what he was elected to do - he will change the establishment. That's what we want - change. That's what we'll get." Bong! The clock starts on Mr Trump's US presidency. Let's take it one day at a time.